This invention relates to electrical connectors and, more particularly, to a contact structure by which a wire is affixed to a contact body, which is then inserted into a connector body.
In one common architecture of electrical connectors, an electrical wire that is to carry an electrical signal or serve as a ground wire is affixed to an generally cylindrical electrically conducting contact. The contact has a hollow tubular portion into which the wire is inserted. The hollow tubular portion is crushed inwardly with a tool, a process termed crimping, to establish the electrical connection between the contact and the wire. The contact structure with the wire crimped thereto is inserted into a connector body and held in place with a retention clip. A contactor portion of the contact makes electrical contact to a conforming connector when the two connectors are assembled together.
This type of connector structure has worked well for many years. Over time, however, there has been a continuing effort to reduce the weight of electrical systems, particularly those in aircraft. One aspect of this weight-reduction effort has been to reduce the diameter of the electrical wires and their insulation whenever possible. The sizes of the connectors have remained the same. However, it has been found that when a wire of diameter smaller than intended for the wire sealing range of the connector is employed, there may be a space between the inner wall of the connector grommet seals and the insulation of the wire where corrodants can find their way into the interior of the connector, leading to corrosion or electrical shorts within the connector.
The connector-manufacturing industry has proposed as a solution to this problem a new generation of connector bodies which are specifically structured for use with smaller wires. This proposed solution would be operable, but it would also entail large changeover expenses for existing electrical systems. It would also require that two (or more) different sizes of connectors be available for use in the future, one size for large wires and one size for small wires.
There is a need for an improved approach to the design and construction of electrical interconnections. The present invention fulfills this need, and further provides related advantages.
The present invention provides an electrical connector system which uses a standard size connector body and a standard size contact, but is suitable for the use of electrical wires of reduced diameter. Only one size of connector body is required for both large-diameter and small-diameter wires. The connector system is required to provide for the exclusion of corrodants even when small-diameter wires are used. The structure cannot be installed improperly, an important advantage especially in aircraft applications where these connectors are principally used. Quality control problems are thereby minimized. The present approach also allows wires of different sizes to be used with a single connector body, while avoiding corrosion problems.
In accordance with the invention, an electrical connector system has an electrical contact structure including an electrically conducting contact. The electrically conducting contact comprises a metallic contact body having a hollow tubular portion suitable for receiving an end of a wire inserted therein and forming a crimping contact to the wire, and a metallic contactor, such as a male pin contactor or a female socket, extending from the contact body. A hollow nonmetallic sleeve, preferably made of a plastic that is color coded, is joined to and extends from the hollow tubular portion of the contact body. The sleeve may be joined to the contact body by an adhesive joint. The sleeve is coaxial with the hollow tubular portion in a region where the hollow tubular portion and the sleeve are joined to each other. The wire may be inserted through an interior of the nonmetallic sleeve and into the hollow tubular portion of the contact body for crimping thereto. Preferably, the electrical contact structure is a solder-free contact structure in which no solder is required to affix the wire to the contact body.
The electrical connector system may further include a wire inserted through the sleeve and into the hollow tubular portion of the contact body and having a crimped connection with the hollow tubular portion. The sleeve seals to the insulation of the wire to prevent intrusion of liquids into the interior of the electrical contact. The electrical connector system may further include an electrical connector body in which the electrical contact structure is received.
In a preferred application, an electrical connector system has an electrical contact structure including an electrically conducting contact comprising a metallic contact body having a hollow tubular portion suitable for receiving an end of a wire inserted therein and forming a crimping contact to the wire, and a metallic contactor extending from the contact body. A hollow nonmetallic sleeve is joined to and extends from the hollow tubular portion of the contact body, so that the sleeve is coaxial with the hollow tubular portion in a region where the hollow tubular portion and the sleeve are joined to each other. A wire is inserted through the hollow interior of the sleeve and into the hollow tubular portion of the contact body and has a crimped connection with the hollow tubular portion. An electrical connector body receives the electrical contact structure. Other features as discussed above may be used with this embodiment.
Presently, Original Equipment Manufacturers (OEMs) assemble electrical connectors with small-diameter wire by using an extra piece of insulation overlying the wire, to build up the wire""s outer diameter to meet the connector wire diameter sealing ranges. Putting such an extra piece of insulation on every wire, and locating it at the connector""s wire seal location, is highly labor intensive. More quality inspection time is required to be certain that the extra insulation is always present. Using the extra insulation increases the procurement and inventory cost due to an additional part being included in the connector assembly. Similarly, this approach requiring the use of additional small pieces of insulation increases procurement, inventory, and labor cost for the maintenance community. It also results in maintenance quality problems, because the extra insulation is often removed and then not replaced during connector repairs. In a modern fly-by-wire aircraft, the loss of such an piece of insulation, which may permit corrodant intrusion into the connector, could become a flight safety issue. The present approach avoids these cost, quality, and safety issues.
The present approach is easy to use in new installations and in repairs. It ensures that the connector always seals around the wire so that corrodants may not penetrate into the interior of the contact body to corrode the crimped connection or cause electrical shorts. The present approach allows one size of connector, a conventional connector design, to be used for both large and small wires. The present design reduces the number of components needed to maintain the wiring system by reducing the number of different types of connectors needed to accommodate a wider range of wire sizes, and avoids the need for unique components to help the connector seal out the external environment.
Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. The scope of the invention is not, however, limited to this preferred embodiment.